This invention relates to automated apparatus and methods for dispensing animal feed. More particularly, this invention relates to a novel feed dispenser system for simultaneously dispensing animal feed in measured quantities at one or more locations.
Breeding and raising various types of animals for human use or consumption is often undertaken today on a large scale, commercial basis. In such cases, it is critical to the success of the operation to ensure that the animals are efficiently fed the appropriate type of feed in the correct amounts at the proper times. Problems associated with proper feeding are perhaps nowhere more apparent than in connection with the breeding and raising of fish.
For example, when raising rainbow trout, the small, newly hatched fish are generally placed in indoor ponds under a controlled environment. For maximum success, these young fish should have the opportunity to feed continually during daylight hours or generally be fed a minimum of ten times per day. Each pond, of course, contains numerous fish, and depending on size and population, the combined fish in a single pond may consume between one ounce and one hundred pounds of fish feed per day.
When the young rainbow trout are one to three months old and two to four inches in length, they are then transferred to larger outdoor ponds. Each fish will likely remain in the outdoor ponds for an additional eight months or more until ready for market. It can thus be appreciated that the outdoor ponds of a typical fish hatchery contain a large number of fish of a variety of different sizes at any given time.
In order to ensure proper feeding, the fish in the outdoor ponds are typically graded by size such that each pond contains fish of the same general size. This also prevents larger fish from monopolizing the feed and thereby endangering the safety and development of smaller fish. Depending upon the size and number of fish in any given pond, the fish in a single pond may require anywhere between twenty and one thousand pounds of fish feed per day.
When feeding fish commercially, either in indoor or outdoor ponds, it is desirable to maintain regular, consistent feeding times. It is also preferable to feed the prescribed amount of feed in small portions, at frequent intervals, over an estimated time frame of up to 16 hours.
The practice of frequently feeding small amounts of feed over an expanded time frame has proven to be economically beneficial in several respects. It allows for the entire population of fish to receive feed during the day resulting in more uniform growth. It also allows for greater digestion time resulting in improved feed to fish weight conversion.
This practice also improves the pond environment and carrying capacity by spreading out the demand for oxygen needed to digest the feed. Conversely it spreads out the production of digestion by-products such as ammonia and carbon dioxide which are detrimental to fish.
Oxygen, ammonia, and carbon dioxide are first the limiting factors to fish growth and health. These chemical parameters become critical as water is reused throughout downstream ponds. The quality of water flowing through the pond is a key factor in determining the tonnage of fish any given pond, and thus any given hatchery facility can produce and support profitably.
With conventional application the fish are typically fed 50 to 100 pounds of feed several times a day. Feeding a large amount of feed all at once initiates frenzied swimming and feeding activities. To support these activities, the fish consume large amounts of oxygen compounding the previous considerations and bringing water oxygen levels dangerously low.
In addition to reducing the consumption of oxygen, a feed dispensing method that minimizes frenzied swimming activity allows solids to settle to the bottom within the pond where they can easily be removed, thus providing a better downstream pond environment and cleaner effluent water.
Taking all these factors into account, the advantages of feeding small amounts of feed at frequent intervals can be appreciated.
It is also highly desirable to regulate the amount of feed provided to the fish so as to coincide as closely as possible to the amount of feed actually prescribed. It is generally considered desirable that the amount of feed provided be within approximately four percent by weight of the actual amount prescribed. This maximizes the use of the feed, insures proper fish growth, ensures accurate inventory of fish and feed, and thus helps control the costs of raising the fish.
Controlling the growth rate of fish towards the desired market size and time frame is an important aspect of management strategy in the aquaculture business. Thus, a feed delivery system that delivers feed very accurately is crucial towards predicting and regulating harvest.
Conventionally, fish hatcheries have employed a staff to feed the fish by hand. This is still frequently employed when feeding small fish in inside ponds. However, the labor costs involved in feeding fish by hand may be quite high, since the fish must be fed periodically throughout an entire eight to sixteen hour day. Additionally, when feeding fish by hand, it is difficult to maintain consistent feeding times, and some variations can also be expected in the amount of feed being used. Therefore, those skilled in the art of raising fish have attempted to develop and use various types of automatic apparatus for dispensing fish feed.
The prior art apparatus for dispensing fish feed typically comprise a hopper or bin located above the fish tank for temporarily storing the fish feed. A small amount of feed from the storage bin is then automatically dispensed at periodic intervals into the fish tank.
For example, some prior art apparatus comprise a means for periodically opening one or more outlets of the feed storage bin so as to permit feed to drop from the storage bin into the fish tank. Then, after a predetermined time period, the outlets of the storage bin are closed.
Other prior art apparatus comprise a measuring cup or bucket positioned under an outlet of the feed storage bin so as to receive a measure of feed therein. At the appropriate time, after the cup or bucket has been filled, the outlet of the storage bin is closed, and the contents of the cup or bucket are dumped into the fish tank. Thereafter, the cup or bucket is repositioned under the storage bin and refilled in preparation for the next feeding time.
In still other prior art apparatus, feed is dispensed from the storage bin by means of a slide member positioned under the storage bin. The slide member has a channel therethrough. In one position, the channel through the slide member is positioned under the storage bin so as to receive a quantity of feed, the associated apparatus housing temporarily preventing the fish feed from falling out of the channel through the slide member. When the slide member is thereafter moved such that the channel through the slide member is no longer in alignment with the outlet of the storage bin, the slide serves to close the outlet of the feed storage bin. At the same time, the channel through the slide member carries a quantity of feed. Finally, the slide member is positioned such that the feed can drop out of the channel through the slide member and into the fish tank.
The prior art apparatus for dispensing fish feed are typically actuated by means of a solenoid, an electric motor with appropriate gearing, or other mechanical or electrical means. Many prior art apparatus are provided with timer devices such that feed can be dispensed at regular, fixed time intervals. Alternatively, some prior art apparatus are demand-type feeders that comprise a trip wire or like means which extends into the fish tank, and the apparatus dispenses a quantity of fish feed each time the fish hit the trip wire. It will be appreciated that the prior art apparatus for dispensing fish feed offer certain advantages over feeding fish by hand. Nevertheless, prior art fish feeding apparatus suffer from a number of significant disadvantages.
The prior art apparatus for dispensing fish feed have typically been fairly complex. Each apparatus generally has numerous mechanical parts, thus making the apparatus fairly expensive to manufacture and maintain.
Prior art fish feeding apparatus, unfortunately, often waste significant amounts of feed. This is particularly the case when using demand-type feeders. Mechanisms for demand-type feeders are difficult to keep in adjustment and require frequent attention. If a mechanism is too tight, too little feed will be dispensed and, conversely, if the mechanism is too loose, too much feed may be dispensed. This can result not only in the loss of feed and fish gain, but also in a degradation of the water quality and the fish rearing environment. Further, wasted feed may dissolve and clog the gills of fish which is detrimental to their health.
Operation of the prior art apparatus often results in shearing and/or grinding the feed pellets into small particles referred to as "fines". Particularly with larger fish, the fines are not eaten and a substantial portion of the feed is lost. If collected, the fines can be remilled into fresh pellets. But once in the water, they break down and clog the fish gills, making it difficult for the fish to draw oxygen from the water.
As mentioned above, different sizes of fish consume different amounts of fish feed in a day. Unfortunately, some prior art fish feeding apparatus do not permit adjustment of the amount of feed dispensed. Other prior art apparatus provide for some adjustment of the quantity of feed being dispensed, but such adjustment often requires the replacement and/or adjustment of internal parts which can frequently be both difficult and time consuming and which may, in some cases, require at least the partial disassembly of the apparatus. Significantly, even those prior art apparatus which do provide for some adjustment of the amount of feed dispensed cannot readily cover the broad range of feed rates which are generally thought to be most desirable in commercial fish hatcheries.
In addition to consuming different amounts of feed, different sizes of fish also require feed of somewhat different consistencies. For example, very young fish may require feed having the consistency of ground flour, while older fish may need to be provided with feed having the consistency of small pellets. Unfortunately, many prior art feeding apparatus cannot handle the entire range of consistencies of feed required, and this necessitates the use of several different types of fish feeders throughout the life of the fish.
Another significant disadvantage of prior art fish feeders is that some of the apparatus are significantly affected by moisture. Some prior art apparatus are formed of metal which can rust or corrode over time. As mentioned above, some prior art apparatus also use fairly complex electrical systems which may render them unsafe to workers who must work in the vicinity of the apparatus.
Also, many of the prior art fish feeders have clogging and bridging problems associated with various consistencies of feed and moisture. When this occurs, the feeders are not functional until the clog or bridge is removed.